Production of fiber-forming polyamides of improved dyeability

ABSTRACT

PROCESS FOR IMPROVING THE DYEABILITY OF HIGH MOLECULAR WEIGHT LINEAR FIBER-FORMING SYNTHETIC POLYAMIDES WHILE RETAINING SUFFICIENT SOLUTION VISCOSITY WHEREIN THERE IS ADDED TO THE INITIAL POLYAMIDE-FORMING MONOMERIC REACTANT, PRIOR TO OR DURING ITS CONVENTIONAL POLYCONDENSATION, (A) AN ALKYLENT DIAMINE SUCH AS HEAMETHYLENE DIAMINE AND (B) A CARBONIC ACID ESTER SUCH AS ETHYLENE CARBONATE. THE RESULTING PRODUCT HAS A MUCH HIGHER AFFINITY FOR ACID DYES WHILE AVOIDING CERTAIN DISADVANTAGES OF ADDING (A) OR (B) ALONE.

Feb. 22, 1972 K. GERLACH ETAL 3,644,298

PRODUCTION OF FIBER-FORMING POLYAMIDES OF IMPROVED DYEABILITY Filed Jan.13, 1969 2 Sheets-Sheet 1 Solution Viscosity (SV)of Polycaprolactam whenadding increasing amounts of Hexamethylenedlamine (Curve l) 'or EthyleneCarbonate (Curve 2) FIG. I

l 1 l l Solution Viscosity (SV) at Polycaprolactam with the added amountof Hexamethylenedimine held constant in each curve while varying theadded amount of Ethylene Carbonate 2.5-

FIG. 2

l I l 0.0 0.5 5.0 I 5 2.0

Mal Ethylene Carbonate MOI of INVENTORS Hexamethylene curve SymbolDlamlne v KLAUS GERLACH WOLFGANG GRIMM o 0.290 HELMUT LINHART -A .384 BY2 if: 3113; www zw ATT'YS Feb. 22, 1 972 K. GERLACH ETTAL 3,644,298

PRODUCTION OF FIBER-FORMING POLYAMIDES 0F IMPROVED DYEABILITY Filed Jan.13, 1969 2 Sheets-Sheet 2 FIG. 3

Solufion Visc0sify(SV) 0f Polycuproluc'tum with reference to addedamounts of M Bis-(,B-hydroxye'rhyl-curbumido)-n-hexune.

1 v l 0.0 i 0.5 |.0 Mol of l,6Bis-(fihyd rokeihylcurbomido)-n -hexuneINVENTORS:

KLAUS GERLACH WOLFGANG GRIMM HELMUT LINHART fl g w eww ATT'YS UnitedStates Patent Office 3,544,298 Patented Feb. 22, 1972 3,644,298PRODUCTION OF FIBER-FORMING POLYAMIDES F IMPROVED DYEABILITY KlausGerlach, Obernan, Wolfgang Grimm, Erlenbach,

and Helmut Linhart, Aschalfenburg, Germany, assignors to Glanzstotf AG,Wuppertal, Germany Filed Jan. 13, 1969, Ser. No. 790,640 Claimspriority, application Germany, Jan. 13, 1968, P 17 20 886.5 Int. Cl.C08g 20/20 US. Cl. 26078 R 14 Claims ABSTRACT OF THE DISCLOSURE It isknown that the afiinity of linear synthetic polyamides for aciddyestuflfs can be improved by increasing the number of terminal aminogroups present in the polymer molecule. This increase in the afiinity,i.e., in the dyeability, can be achieved by adding various aminocompounds to the monomers which are polycondensed to form the polyamide,e.g. where the monomers are lactams, w-amino-carboxylic acids or themixtures and salts of dicarboxylic acids and diamines. However, thisincrease in dyeability is always accompanied by a deterioration in thephysical properties of the polyamide and of the filaments, threads orfibers which are produced from these polymers. This deterioration isessentially caused by the fact that these amino additives act aschain-breaking agents as evidenced by a reduction in solution viscosity.For example, if caprolactam is polymerized in the presence of only 0.3mol percent of a diamine, a polyamide with a solution viscosity (1 ofonly 2.07 is obtained, whereas the solution viscosity of a polyamideproduced without such as additive is 2.29. An addition of 0.4 molpercent of the diamine lowers the solution viscosity of the polyamide toa value of only 1.96. It will be found by experience that considerabledifiiculties are encountered when spinning polyamides having such lowsolution viscosities, since the melt tends to form drops duringextrusion or spinning in the spinneret. Furthermore, it is not possibleto spin such polyamides of low viscosity into filaments having asatisfactory profile or shaped cross-section, such as those which arerequired for a variety of uses, e.g. for carpet yarns or for very finedenier filaments and yarns which are to be texturized.

In order to obtain a greater improvement in the dyeability without atthe same time reducing the viscosity of the polyamide too much, attemptshave been made to add certain compounds which counteract or inhibit thechain-breaking effect. Phosphoric and phosphonic acid esters havegenerally been proven to be suitable for this purpose. The addition ofboth diamines and phosphoric or phosphonic acid esters is only possible,however, within certain limits. This result arises because, while thephosphorus compounds are certainly able to minimize the decrease inviscosity, they also lead to a cross-linking of the polyamide andconsequently to a different type of deterioration in the spinningproperties or the final fiber properties.

Carbonic acid esters have been used as reaction accelerators in theso-called ionic polycondensation of lactams, which is catalized byalkali or alkaline-earth metals or their hydrides, amides, hydroxides,oxides, alkoxides or carbonates. Under the particular conditions ofionic polycondensation, these carbonic acid esters make it possible toreduce the reaction temperatures and also lead to a shortening of thereaction times. The conventional lactam polycondensation reactions,which are usually carried out in the presence of more or less largequantities of water, show no improvement in processing conditions whenadding the carbonic acid esters.

An object of the present process is to improve the dyeability of linearfiber-forming polyamides, while at the same time maintaining the normalviscosity values and other physical properties of not only the polymersbut also the threads, filaments, fibers, bristles or other shapedproducts which can be produced from the polymers. Other objects andadvantages of the invention will become more apparent upon considerationof the following detailed disclosure.

It has now been found in accordance with the invention that thedyeability with acid dyes of a fiber-forming synthetic linear polyamideas obtained from lactams, w-aminocarboxylic acids or the substantiallyequimolar mixtures and salts of dicarboxylic acids and diamines, can beimproved without impairing the other desirable properties of thesepolyamides if certain alkylene diamines and carbonic acid esters areadded as a synergistic combination to the initial monomeric reactant forthe polyamide or to the reaction mixture during its polycondensation.

More particularly, the invention provides a process for improving thedyeability of those fiber-forming polyamides prepared by theconventional polycondensation of a monomeric reactant selected from theclass consisting of lactams, w-aminocarboxylic acids or the mixtures andsalts of a substantially equimolar proportion of dicarboxylic acids anddiamines, which process comprises carrying out the polycondensation withan addition of (A) 0.1 to 0.75 mol percent of a diamine of the formulain which R is an alkylene group containing 2 to 12 carbon atoms, ahydroaromatic ring structure with 5 or 6 carbon atoms or the group:

wherein m and n are numbers from 1 to 5; or an aliphatic polyamine ofthe formula wherein m is a number from 1 to 6 and n from 1 to 4, and (B)0.1 to 2.5 mol percent of a carbonic acid ester of a primary orsecondary monoor dihydric alcohol, the molar percentages being takenwith reference to the number of mols of the monomeric reactant. It ispreferred to use 0.3 to 0.6 mol percent of the alkylene diamine and 0.1to 1.0 mol percent of the carbonic acid ester. It is particularlypreferred to use 0.3 to 0.5 mol percent of the carbonic acid ester.

In referring to a conventional polycondensation of certain monomericreactants to produce a fiber-forming polyamide, it will be understoodthat the polycondensation reaction is to be carried out in the presenceof a substantial amount of water, e.g. at least 2% by weight withreference to the total reaction mixture, i.e. as an aqueous solution ofthe monomeric reactant. No special catalyst is required in thisconventional polycondensation reaction, and in fact it is preferable toavoid the use of a catalyst as such, since the reaction proceeds readilyin the presence of water as is well known. The polycondensation ispreferably carried out or at least initiated under an inert atmosphere,e.g. nitrogen, and the reaction temperature is in the conventional rangeof about 270 to 280 C.

It should be noted that the monomeric reactant may be a lactam such ascaprolactam or higher lactams up to about 12 carbon atoms or anw-aminocarboxylic acid characterized by an alkylene hydrocarbon chain,e.g. of 6 to 12 carbon atoms, with the amino group (NH at one end andthe carboxyl group (-COOH) at the other end, or it may be a mixture orsalt of the usual aliphatic dicarboxylic acids and aliphatic diamines inwhich each component of the mixture or salt is present in substantiallythe same molar amount. Thus, in this latter case Where one uses anacid-amine salt, e.g. the so-called AH- salt which is also referred toas hexamethylene diammo nium adipate, the total mols of the monomericreactant should include the mols of the dicarboxylic acid plus the molsof the diamine, just as these would be separately calculated in a simplemixture of the two components.

The polycondensation step of the invention is thus con ventional exceptfor the addition of the alkylene diamine (A) and the carbonic acid ester(B). In general, it is desirable to conduct the polycondensation for aperiod of time sufficient to provide a solution viscosity of thecondensed product of about 2.10 to 2.60.

It is especially desirable to use straight-chain alkylene diamines withterminal primary amino groups as component (A) of the invention.However, those diamines having a branched chain or diamines witharomatic or hydroaromatic groups can also be employed, provided thatthey do not contain any other functional substituents, apart from theamino groups. Saturated aliphatic diamines with secondary amino groupsmay be used, e.g. the various polyalkylene polyamines. In general, thesediamines preferably contain about 2 to 8 carbon atoms, and particularlygood results are achieved with hexamethylene diamine. When using thisspecific diamine in combination with a monomeric reactant of the samecompound, it will be understood that the amount of the additive (A) inaccordance with the invention represents an excess over that amountrequired as an initial monomer.

Among many suitable alkylene diamines falling within the above-notedlimitations, the following can set forth by way of example:

Ethylene dlamino p-Xylylenediamine Butylene diamine Hexamethylenediamine p-Phenylenediethylenediamino 4 (2) Neutral cyclic carbon acidesters from aliphatic or hydroaromatic or aliphatic-aromatic di-alcoholsof the formula in which R and R are aliphatic side chains oralkoxygroups with up to 6 carbon atoms. Ethylene carbonate isparticularly suitable. However, carbonates of higher aliphaticdi-alcohols and aliphatic mono-alcohols can also be used. Carbonic acidesters of aromatic compounds, e.g. diphenyl carbonate, can also be used.In general, it is preferable to employ relatively low molecular weightcarbonic acid esters, e.g. of from 3 to 13 carbon atoms and especially 3to 7 carbon atoms, including the carbon atom of the carbonic aciditself. These carbonic acid esters are essentially difunctionalcompounds or socalled diesters but they may be open-chained or cycliccompounds. For example, when using a dihydric alkanol to obtain theester, it easily forms the ring structure:

Decamethyleno diamine NH CH; CH2-CHz-- CH2-NH Dodecamethylene diaminoDiethylene triamine Triethylene tetramine Tetraethylene pentaminoDlpropylene trianiine in which R and R are alkyl groups containing 2 to12 carbon atoms respectively hydroaromatic rings with 5 to 6 carbonatoms or arylor alkaryl groups with side chains w th p to 1.2 carbonatoms.

where n is an integer of 2 or more. In addition, the alkylene portion ofthe ring may bear a lower alkyl substituent, preferably methyl, so as toyield a substituted cyclic ring. Preferred esters of this type are:

Ethylene carbouato 0J.[2 C1[2 On the other hand, monohydric alcohols canbe used to form the open-chain diester of carbonic acid of the generalformula:

O H Diplicnyl carbonate Q O-C O'@ 0 CH CHQO FIG. 1 is a graph of thesolution viscosity (SV) of a polycaprolactam measured against theincreasing molar percent of the addition solely of hexamethylene diamine(curve 1) and the addition solely of ethylene carbonate (curve 2).

If, however, the polycondensation of the lactam is carried out accordingto the invention, that is to say, with the addition of both a diamine(A) and a carbonic acid ester (B), then not only does the dyeabilityimprove but the solution viscosity is found to increase with anincreasing quantity of carbonic acid ester (see FIG. 2).

FIG. 2 is a graph of the solution viscosity (SV) of a number ofpolycaprolactams containing different amounts of hexamethylene diamine,showing the effect of in- The two additives, i.e. the diamine andcarbonic acid ester, can be added separately or in admixture with eachother. This addition can take place prior to the polycondensation byadmixture with the initial monomeric reactant required to produce thefiber-forming polyamide, or it can take place after the polycondensationhas been initiated, preferably within the first one-third of thepolycondensation reaction. The reaction which takes place in thepresence of both components (A) and (B) is too complex to be determinedwith any degree of accuracy, although it is believed both componentsbecome incorporated in the polyamide chain and that this occurs in amanner which not only improves dyeability but also maintains a highsolution viscosity. There may also be some reaction between components(A) and (B), although this appears to be relatively unlikely since theresults achieved are not strongly affected by the molar ratio of (A):(B)which may fall in a range of about 7.521 to 1:25. The most desirableresults are achieved in a range of (A):(B) of about 5:1 to 112.

No alteration of the conventional processing conditions used during theproduction of the polyamides or during the spinning of filaments isnecessary. The polyamides can also be delustered in known manner byadding titanium dioxide. It is also surprisingly found that relativelylarge quantities of the delustering agent, e.g. 1.8 to 2.0% by weight,based on the polyamide, may be added without any agglomeration of thepigment particles taking place. Thus, it was to be expected that thepresence of the additives according to the invention would cause thetitanium to fiocculate out, since this is known to occur withelectrolytes.

The polyamides produced by the process according to the invention arecompletely white and are suitable for manufacture of filaments, threads,bristles, films and other shaped articles.

If, as described above, only the carbonic acid ester is added as areaction acceleator to provide an ionic polycondensation of the lactam,the process being carried out under normal conditions and withincreasing quantities of the carbonic acid ester being added to thelactam-water mixture, then the solution viscosity of the polyamide whichis formed is considerably reduced. In the same way, and even morenoticeable decrease in the solution viscosity of the polyamide productis found when only the diamine is added (see FIG. 1 of the accompanyingdrawings).

creasing the content of ethylene carbanate. Curves 1, 2, 3 and 4 of FIG.2 thus represent polyamides containing 0.290, 0.384, 0.481 and 0.576 molpercent of hexamethylene diamine, respectively. The points on the curves1, 2, 3 and 4 are prepresented, respectively, by a circle, a triangle, asquare and a cross.

This effect is quite surprising and was not foreseeable, especiallysince the reaction products 1,6-bis (fi-hydroxyethylcarbamido)-n-hexaneand l-(li-hydroxyethylcarbamido)-6-amino-n-hexane, which are formed, forexample, from ethylene carbonate and hexamethylene diamine at moderatelyelevated temperatures, are very effective as chain-breaking agents and,with an addition of comparable quantities, reduce the solution viscosityalmost asstrongly as hexamethylene diamine itself (see FIG. 3).

FIG. 3 is a graph of the solution viscosity (SV) of a polycaprolactamwhich contains an increasing mol percent of1,6-bis(hydroxymethyl-carbamido)-n-hexane. The term carbamido in namingthese compounds is intended to identify the divalent radical NH-COO-,sometimes identified as the carbamic radical.

The process is further illustrated by but not limited to the followingexamples.

EXAMPLE 1 A mixture of 4,750 g. of caprolactam, 250 g. of water andvarious quantities of the diamine and carbonic acid ester additives, isheated in a closed autoclave under nitrogen for one hour until thepressure has risen to 18 atm. The pressure is then released oved aperiod of 1% hours, the temperature of the melt being kept at 270 C.After this, oxygen-free nitrogen is passed over the melt for two hoursand then the polyamide is withdrawn in a conventional manner in the formof a strip, band or rod while cooling. After granulation, the polyamidecuttings are extracted by boiling with water in order to remove lowmolecular weight fractions and are dried until they have a water contentof 0.03%.

The values of the solution viscosities of the polyamide product and ofthe threads or fibers which are produced therefrom and the dataconcerning the dyeability are given in Table I, as follows. (Thecomparison samples were prepared under the conditions given in Example1, but without addition of diamine and carbonic acid ester,respectively. However, as stabilizer 8.2 g.0.l6 mol percent-of benzoicacid was employed.)

TABLE II.Continued SV oi Percent Mol granulated SV of ExampleComposition by wt! percent material threads Extinction values/dyeingfactor (F) 6,000.0 g. AH-salt 2(i) 4 000.0 g. water 2. 22 2. 30

5 90 g. hexamethylene diamine. 0.5 0. 485 Sample, 0.830; Comparison,0.163/F, 5.1. 5.09 g. ethylene carbonate 0.1 0. 128 6,000.0 g. AH-salt2(g) 4,000.0 g. water 2. 24 2. 41

25.90 g. hexamethylene diamine. 0. 5 0. 482 Sample, 0.850; Comparison,0.155/F, 5.5. 25.90 g. ethylene carbonate" 0. 5 0.636 6,000.0 g. AH-salt2(h) 4,000.0 g. water 2. 11 .37

g .10 g. hexamethylene diam1ne 0. 583 Sample, 0.810; Comparison,0.130/F, 6.2. 6. 2(1) 6 31.10 Sample, 0.860; Comparison, 0154/1 5.6.(155 0.382 2(j) 2.01 2.26

38.85 0.75 0.724 Sample, 0.890; Comparlosn, 0137/13, 6.5. 5.09 g.ethylene carbonate. 0. 1 0. 128 6,000.0 g. AH-sa1t 2(k) ,000.0 2.06 2.36

38.85 g. hexamethylene diamine. 0.75 0. 724 Sample, 0.770; Comparison,0.100/F, 7.7. 10.36 g. ethylene carbonate 0.2 0. 255

*Bascd on 100 parts by weight of condensate (AH-salt).

EXAMPLE 3 The following examples serve to illustrate the technical Amixture consisting of 95 parts of caprolactam, 5 parts of water, 0.475part (=0.484 mol percent) of hexamethylene diamine and 0.19 part (=0.255mol percent) of ethylene carbonate, to which are added 1.02 parts of awater-containing titanium dioxide paste with a TiO content of 28% byweight, is polycondensed in a conventional manner in a VI tube. Theresidence time of the reaction mixture in the VK tube is about 22 hours.The polyamide is withdrawn in the form of a Strip and granulated. Afterthe usual extraction, a solution viscosity of 2.1 is found. The TiOcontent amounts to 0.3%.

EXAMPLE 4 Example- SV oi cuttings SV of filaments. Dyeing factor (F)Extinction Extinction (comparison sampl (The comparison samples wereprepared under the conditions given in Examples 3 and 4, but withoutaddition of diamine and carbonic acid ester, respectively. However, asstabilizer 0.16 mol percent of benzoic acid was employed.)

advantages ofiFered by the process according to the invention, whencompared with known procedures, in which diamines or carbonic acidesters alone were used in the polycondensation of polyamides. Inaddition, the effect of adding a reaction product of a diamine and acarbonic acid ester is also shown.

COMPARISON EXAMPLE A The polycondensation of caprolactam is carried outas given in Example 1, an increased quantity of hexamethylene diamine,but no carbonic acid ester, being used as the additive. The results ofthe tests are given in Table III below. While a comparatively largeincrease in the dyeability is obtained, the solution viscosities alsodecreased considerably.

COMPARISON EXAMPLE B Example 1 is repeated, but with addition of1,6-bis- (fl-hydroxyethyl-carbamido)-n-hexane, which is the reactionproduct of 2 mols of ethylene carbonate and 1 mol of hexamethylenediamine. The results of the tests are shown in Table V below, from whichit can be seen that, with a good rise in the dyeability, the solutionviscosity decreases with an increasing quantity of the additive.

TABLE III SV 01 omparison Percent Moi granulated SV 01 Extinctionvalucs/ E xample Composition by wt. percent material threads dyeingfactor (F) A(a) 4,750.0 g. eaprolactam 250.0 g. water 2. 29 2. 58 A(b)4,750.0 g. caprolactam. Sample 0. 845 250.0 g. water s 2.07 2. 23Comparison. 0. 165 14.3 g. hexamethylene diamine. F 5. 1 A(c) 4,750.0 g.caprolactam 0. 700 250.0 g. water .s 0. 113 10.0 g. hexamethylene di 7.0 A01) 4,750.0 g. caprolactam- 0. 010 250.0 g. water 0. 23.75 g.hexamethylene diamine- 7. 3 11(0) 4,750.0 g. caprolactam 0. 845 250.0 g.water 0. 39%

28.5 g. hexamethylene diamine 1 Based on caprolactam.

TABLE IV SV oi granu- Comparison M01 lated SV of Dyeing ExampleAdditives 1 percent 2 material threads Extinctions factor B(a) 11.88 g.ethylene carbonate 0.322 2.30 1 6 13(1)) 23.76 g. ethylene carbonate 0.643 2. 24 I; L 6 13(0) 35.68 g. ethylene carbonate 0. 965 2. 24 L 813(d) 47.50 g. ethylene carbonate 1. 242 2.18 1 1 13(e) 59.39 g.ethylene carbonate 1.607 2. 01648 2 0 1 Quantities added to the initialmixture: 4,750 g. caprolactani and 250 g. water. 2 Based oncaprolactain.

TABLE V SV of granu- Comparison Mol lated SV of Dyeing Example Additives1 percent 2 material threads Extinctlons factor 0 a 23.75 g.1,6-bis-(d-hydroxyethyl 0.820

a aze-era sea 1 3 .62 g. isy oxye iy carbamdgoyrzc-ihfixaine. th 1 0'291C(e) 47.50 g. 1, isy roxye y carbamido)-n-hcxane. 0387 12 icomparisonun-0.160} g I C(d) 59.88 g. 1,6-bis-(d-hydroxyathyl 0. 500 1. 96 2. 05Sample 0. 900 6. 9

carbamido)-n-hexane. C(e) 71.75g.1,6-bis-(d-hydr0xyethyl 0.585 1.90 2 00Sample 893} g 5 7 8 carbamido)-n-hexane. 1Comparis0n 0 115 1 Quantitiesadded to the initial mixture 14,750 g. caprolactam and 250 g. watc r.

2 Based on caprolactam.

The following description relates to the determination monomericreactant in the presence of at least about 2% of solution viscosity (SV)and the dyeing factor (F) as 30 by weight of water, with reference tothe total reaction set forth in the preceding examples and also in thegraphs of the drawing:

The solution viscosity (SV) is determined as a 1% by weight solution ofthe polyamide product in 90% formic acid at C.

In order to establish the dyeability, sample of knitwear fabric areproduced both from the filamentary material to be tested and from acomparison thread, and the samples are dyed and tested in accordancewith the following steps.

The samples are washed with a non-ionic detergent in a bath adjustedwith acetic acid to a pH value of 5 and then rinsed with water.

For the dyeing operation, an aqueous dyestutf solution is used. Thissolution, based on the weight of the samples or specimens, contains 1%of Anthralanblau B (Acid Blue 41, Colour Index No. 62,130) and anon-ionic wetting agent. The bath solution ratio is 1:50. The samplesare placed in the cold dye bath solution, which is then heated during 45minutes to its boiling point and is maintained for another 15 minutes atthis temperature. It is then cooled and dilute acetic acid is added tothe dye bath to adjust the pH value to 5. The dyeing is then fixed byboiling for 10 minutes. The samples are washed with water and dried.

In order to establish the quantities of dyestuif absorbed, 500 mg. ofthe sample and comparison fabric materials are each completelydecolorized with 100 ml. of aqueous pyridine. The extinctions of thedyestulf solutions thus obtained are determined with a spectralphotometer at a wavelength of 640' millimicrons.

The dyeing factor F is given by the equation:

Extinction of the test solution Extinction of the comparison solutionmixture, and with an addition to said monomeric rcactant of a mixture ofreactive components consisting essentially of (A) 0.1 to 0.75 molpercent of a diamine of the formula H N-RNH in which R is an alkylenegroup containing 2 to 12 carbon atoms, a hydroaromatic ring structurewith 5 or 6 carbon atoms or the group:

wherein m and n are numbers from 1 to 5; or an aliphatic polyamine ofthe formula H N'(CH CH -(NHCH -CH N H wherein m is a number from 1 to 6and n from 1 to 4, and

(B) 0.1 to 2.5 mol percent of a carbonic acid ester of an alcoholselected from the class consisting of primary and secondary monoanddi-hydric alcohols, the molar percentages being taken with reference tothe number of mols of the monomeric reactant.

2. A process as claimed in claim 1 wherein component (A) is added in anamount of 0.3 to 0.6 mol percent and component (B) is added in an amountof 0.3 to 0.5 mol percent.

3. A process as claimed in claim 1 wherein the initial monomericreactant is caprolactam.

4. A process as claimed in claim 1 wherein the initial monomericreactant is hexamethylene diammonium adipate.

5. A process as claimed in claim 1 wherein components (A) and (B) areadded separately at a point prior to or during the polycondensation ofthe initial monomeric reactant.

6. A process as claimed in claim 1 wherein components (A) and (B) areadded in admixture with each other at a point prior to or during thepolycondensation of the initial monomeric reactant.

7. A process as claimed in claim 1 wherein component (A) ishcxamethylcne diamine and component (B) is ethylene carbonate.

8. A process as claimed in claim 1 wherein component (A) is ethylenediamine and component (B) is ethylene carbonate.

9. A process as claimed in claim 1 wherein component (A) isdecamethylene diamine and component (B) is ethylene carbonate.

10. A process as claimed in claim 1 wherein component (A) ishexamethylene diamine and component (B) is diethyl carbonate.

11. A process as claimed in claim 1 wherein component (A) ishexamethylene diamine and component (B) is 1,2-propylene carbonate.

12. A process as claimed in claim 1 wherein component (A) ishexamethylene diamine and component (B) is diphenyl carbonate.

13. A process as claimed in claim 1 wherein component (A) is an alkylenediamine containing secondary amino groups in a linear alkylene chainhaving terminal primary amino groups.

UNITED STATES PATENTS 2,241,321 5/1941 Schlack 26078 2,835,653 5/1958Haas et al. 26078 3,239,490 3/1966 Gee et al 26078 3,304,289 2/1967Ballentine et al. 26078 3,437,641 4/1969 Lenz et al. 26078 HAROLD D.ANDERSON, Primary Examiner US. Cl. X.R.

26077.5 D, 78 A, 78 L, 78 TF mg I UNITED STATES FATENT OFFICECERTIFICATE OF CORRECTlON Patent No. 5 h 9 Dated F r ary 22., 1972Inventor(s) Klaus Gerlach, Wolfgang Grimm, and Helmut Linhart It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 5, lines 25 to 28, "Di-[ -phenethyl-carbonate Q CH -CH-O-(C|-O--CH2-CH2 should read o Di-fl-phenylethylcarbonate Q cH -cH -0--o-cH2-cH2 Column 5, line 67, "acceleator" should read acceleratorColumn ll, Table V, under "additives", examples "C(a)" through "C(e)",each occurrence, "1,6-bis-d-hydroxyethyl" should read l,6-bis-[-hydroxyethyl line 56, "sample" should read samples Signed and sealedthis 3rd day of October 1972.

(SEAL) Attest:

EDWARD MOFLLTCHER ,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

